Eastern Hop Hornbeam (Ironwood)

Ostrya virginiana

Hop_Hornbeam_Ostrya_virginiana.jpg

Illustration of hop hornbeam leaves, twig, fruit.
Hop hornbeam, Ostrya virginiana
Paul Nelson
Family

Betulaceae (birches)

Description

Eastern hop hornbeam is a small tree with wide, spreading branches.

Leaves are alternate, simple, blades 2½–4½ inches long, 1½–2½ inches wide, broadest at or below the middle; margin sharply and densely toothed; base often uneven; upper surface yellowish to dark green, dull; lower surface paler, hairy.

Bark thin, reddish gray, with narrow, platelike, tight scales; some trees with loose, shreddy scales.

Twigs usually slightly zigzag, hairy toward the tip, reddish brown to dark brown, pores small, not obvious.

Flowers in April–May, before the leaves, on male and female catkins and on the same twig.

Fruit in conelike clusters of overlapping, scalelike sacs, overall resembling hops (hence the name), 1½–2 inches long; each sac papery, white, and containing a single nut.

Size

Height: to 24 feet.

Eastern_Hophornbeam_Fruits_Gans_Creek_8-12-06.jpg

Photo of eastern hop hornbeam leaves and fruits
Eastern Hop Hornbeam Fruits
Eastern hop hornbeam is named for its fruits, which are clusters of flattened, papery, scalelike sacs arranged in an overlapping pattern, like scales on a pinecone — resembling the hops that beer is made from.

Hop_Hornbeam_leaves_Maramec_Spring_6-4-17.jpg

Photo of hop hornbeam showing leaves and developing fruit cluster
Hop Hornbeam Leaves
Hop hornbeam leaves are alternate, simple, and sharply and densely toothed. Upper surface is dull; lower surface is hairy.

Hop_Hornbeam_bark_Maramec_Spring_6-4-17.jpg

Photo of mature hob hornbeam trunk showing bark
Hop Hornbeam Bark
The bark of hop hornbeam is thin, reddish gray, with tight, narrow, platelike scales; some trees have loose, shreddy scales.

hophornbeam1.jpg

hop hornbeam
Hop Hornbeam
Habitat and conservation

Occurs in fairly dry soil on rocky slopes, along bluffs, in upland woods, and rarely along streams. A common understory tree in oak-hickory forests, along with flowering dogwood, sassafras, redbud, and serviceberry. Sometimes called ironwood because of the extreme hardness of the wood. Because the catkins of this tree are such an important winter food for ruffed grouse, this species is important to have in areas where ruffed grouse populations are being encouraged.

image of Hop Hornbeam distribution map
Distribution in Missouri

Statewide, mostly excluding the far southeast corner and the central portion of the state’s western edge.

Human connections

One of the hardest and strongest woods, harder than oak, hickory, locust, and more, surpassed only by flowering dogwood — hence its name “ironwood.” Because the tree is small, use is limited to tool handles, mallets, and posts. It makes a nice ornamental tree. In the past, the bark was used medicinally.

Ecosystem connections

Birds, including quail and wild turkey, eat the fruits. The catkins and buds are the most important late autumn, winter, and early spring food for ruffed grouse.